20.500.12556/DKUM-95915 Surface analysis of sodium metamizolate as an active pharmaceutical ingredient in solid form This study focuses on the surface and subsurface characterization of a pharmaceutical tablet containing sodium metamizolate (NaMET), with an emphasis on mass spectrometry using time-of-flight secondary ion mass spectrometry (ToF-SIMS). ToF-SIMS enabled the identification of NaMET-specific fragment ions, which served as signals for the determination of the spatial distribution of this active pharmaceutical ingredient (API) within the tablet matrix. A ToF-SIMS fragmentation mechanism for NaMET was proposed based on the ToF-SIMS spectra analysis measured on a NaMET reference standard. 3D ToF-SIMS imaging showed heterogeneous localization of the API across a 5 μm depth. Complementary techniques, including 3D profilometry and atomic force microscopy (AFM), provided surface roughness and morphological data, while X-ray photoelectron spectroscopy (XPS) confirmed the elemental composition and chemical states. Depth profiling by XPS further supported the non-uniform distribution of NaMET. matamizole sodium metamizolate ToF-SIMS XPS surface analysis API metamizol farmacevtska zdravila spektrometrija true false false Elsevier B. V. Angleški jezik Slovenski jezik https://www.sciencedirect.com/journal/international-journal-of-mass-spectrometry © 2025 The Authors Članek v reviji 2025-11-10 08:59:30 2025-11-10 08:59:30 2025-11-11 03:08:47 0000-00-00 00:00:00 2026 0 0 10 str. Vol. 519, [article no.] 117548 Jan. 2026 0000-00-00 Zaloznikova Objavljeno NiDoloceno 2025-07-15 2025-10-29 2025-11-05 661.12:615 256060931 10.1016/j.ijms.2025.117548 1873-2798 1-s2.0-S1387380625001526-main.pdf 1-s2.0-S1387380625001526-main.pdf 1 119AA6E41FD06A48BCEF2DBEA5951777 9db945597f2c111ae1d274a89e81dfd60703326e3597a318e4b629425f6c95f7 96e030a0-be0b-11f0-8bb8-00155d000105 https://dk.um.si/Dokument.php?lang=slv&id=200500 Fakulteta za kemijo in kemijsko tehnologijo 0 0 0